This invention relates generally to pool cleaning systems of the type including a so-called automatic pool cleaning device adapted to traverse submerged surfaces of a swimming pool or the like to pick up and collect accumulated debris such as leaves, twigs, sand and silt. More particularly, this invention relates to an improved swivel coupling for interconnecting a pool cleaner with a flexible hose or the like used for coupling the pool cleaner to an hydraulic power source such as a suction or vacuum source by connection to the suction side of a conventional pool water filtration system. The improved swivel coupling of the present invention is designed to provide substantial and relatively free rotational swivel displacement between the hose and the pool cleaner, substantially without binding or interference attributable to ingestion of debris and grit.
Pool cleaner systems and related devices are generally well known in the art for use in maintaining residential and commercial swimming pools in a clean and attractive condition. In this regard, swimming pools conventionally include a water filtration system equipped with a pump for drawing or suctioning water from the pool for circulation through a filter canister having filter media therein to remove and collect water-entrained debris such as leaves and twigs as well as fine particulate including sand and silt. In a typical arrangement, at least a portion of the pool water is vacuum-drawn over a weir mounted within a so-called skimmer well positioned substantially at the water surface to draw and collect floating debris to the filter equipment. From the filter canister, the water is recirculated to the pool via one or more return lines. Such filtration equipment is normally operated for several hours on a daily basis and serves, in combination with traditional chemical treatments such as chlorination or the like, to maintain the pool water in a clean and clear sanitary state.
The water filtration system is generally ineffective, however, to filter out debris which settles onto submerged floor and side wall surfaces of the swimming pool. In the past, settled debris has typically been removed by coupling a vacuum hose to the suction side of the pool water filtration system, such as by connecting the vacuum hose to the skimmer well located near the water surface at one side of the pool, and then manually moving a vacuum head coupled to the hose over the submerged pool surfaces to vacuum settled debris directly to the filter canister where it is collected and separated from the pool water. However, manual vacuuming of a swimming pool is a labor intensive task and is thus not typically performed by the pool owner or pool cleaning service personnel on a daily basis.
So-called automatic pool cleaner devices have been developed over the years for cleaning submerged pool surfaces, thereby substantially eliminating the need for labor intensive manual vacuuming. Such automatic pool cleaners typically comprise a relatively compact cleaner housing or head coupled to the pool water filtration system by a hose and including water-powered means for causing the cleaner to travel about within a swimming pool to dislodge and collect settled debris. In one form, the pool cleaner is connected to the return or pressure side of the filtration system for receiving positive pressure water which powers a turbine for rotatably driving cleaner wheels, and also functions by venturi action to draw settled debris into a filter bag. See, for example, U.S. Pat. Nos. 3,882,574; 4,558,479; 4,589,986; and 4,734,954. In another form, the pool cleaner is coupled by a vacuum hose to the suction side of the filtration system, whereby water is drawn through the pool cleaner to operate a drive mechanism for transporting the cleaner within the pool while vacuuming settled debris to the filter canister of the pool filtration system. See, for example, U.S. Pat. Nos. 3,803,658; 4,023,227; 4,133,068; 4,208,752; 4,643,217; 4,679,867; 4,729,406; 4,761,848; 5,105,496; 5,265,297; and 5,634,229. See also, copending U.S. Ser. No. 09/090,894, filed Jun. 4, 1998, and U.S. Ser. No. 09/176,532, filed Oct. 21, 1998.
In a typical pool cleaner installation, one or more swivel couplings are installed along the length of the flexible hose to enable the pool cleaner to travel a substantially random path to traverse and clean submerged pool surfaces, without significant hose twisting which could otherwise impact and restrict random cleaner travel. In this regard, the pool cleaner installation normally includes a swivel coupling for interconnecting a distal end of the flexible hose to a water flow port on the pool cleaner. Additional swivel couplings may also be installed in-line along the length of the hose, if desired. However, particularly with a suction powered pool cleaner wherein water is drawn through the flexible hose at a negative pressure, these swivel couplings are susceptible to ingestion of debris such as fine dirt and grit. Such ingested dirt and grit can accumulate between moving surfaces of the coupling and eventually cause the coupling to bind or lock up. When this occurs, it is necessary to disassemble the swivel coupling for cleaning, or to replace it.
The present invention relates to an improved swivel coupling for use with a pool cleaner, particularly of the suction powered type, wherein the swivel coupling is resistant to ingestion of debris such as dirt and grit, and further wherein any ingested dirt and grit is flushed through the swivel coupling to prevent accumulation therein.